The invention relates to tool couplers for excavation, demolition and construction equipment.
Some types of construction equipment, such as backhoes and excavators, have a movable dipperstick (also referred to as an arm) to which a variety of tools, such as, for example, buckets and grapples, can be attached. A hydraulic linkage allows the equipment operator to pivot the tool from the free end of the dipperstick. To simplify the process of changing tool attachments, a universal coupler can be fixed to the dipperstick linkage. A selected tool can then be removably attached to the coupler, a process that typically involves manually positioning at least one latch pin between the coupler and the tool.
There is a trend in the industry to use an actuated coupler on the end of the dipper stick for connecting and disconnecting a tool from the linkage. A great advantage of these systems is that the operator can actuate the coupler to connect or disconnect a tool without the assistance of another worker and without having to leave the cab of the vehicle.
One type of actuated coupler first engages a crossbar formed in the tool with hooks depending from the coupler, and then engages a latch pin (or a block or a wedge) with a mating receptacle formed in a collar on the tool. A double-action hydraulic cylinder in line with the latch pin is positioned so that the cylinder extends to push the latch pin into the receptacle. In disengaging the tool from the coupler, the operator retracts the rod into the cylinder body, pulling the pin out of the receptacle.